1. Field of the Invention
This invention relates generally to electronic tone generation and processing and more particularly, it relates to an interface circuit for converting analog signals from a musical instrument and/or a microphone to digital pulse signals for use with electronic musical synthesizers and the like.
2. Description of the Prior Art
A prior art search directed to the subject matter of this application in the U.S. Patent and Trademark Office revealed the following U.S. Letters Patent:
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As is generally known to those skilled in the electronic musical instrument art, electronic music synthesizers are used to create varied musical sounds by generating and processing various basic waveforms to provide a desired sound. The music synthesizer generally utilizes a musical instrument or a signal from a microphone to derive an input source. The output signals from the musical instrument or microphone are basically a time-varying analog waveform. On the other hand, most modern music synthesizers such as electronic keyboard instruments and the like are substantially digital in operation. In other words, these synthesizers utilize digital circuit components to receive the various input signal sources for generating and reconstructing the various and sundry sounds. Thus, the synthesizers generally require strictly digital pulse signals (which are either high or low signals) or "dynamic" or quasidigital pulse signals (which are digital pulse signals coupled with a time-varying amplitude signal).
Heretofore, there has been no reliable means to interface the analog output signals from musical instruments or a microphone in a simple manner with the music synthesizers requiring digital pulse signals. The present invention provides such an interface circuit for converting analog signals from a musical instrument and/or a microphone to digital pulse signals for use with electronic music synthesizers and the like. The output signals from the interface circuit provide both digital pulse signals as well as dynamic digital pulse signals in response to the time-varying analog input signals.